docs: def config(p_path=None, p_overrides=None):
      """
      Retrieve the config instance.
  
      If a path is given, the instance is overwritten by the one that supplies an
      additional filename (for testability). Moreover, no other configuration
      files will be read when a path is given.
  
      Overrides will discard a setting in any configuration file and use the
      passed value instead. Structure: (section, option) => value
      The previous configuration instance will be discarded.
      """
      if not config.instance or p_path is not None or p_overrides is not None:
          try:
              config.instance = _Config(p_path, p_overrides)
          except configparser.ParsingError as perr:
              raise ConfigError(str(perr)) from perr
  
      return config.instance